So-called rock anchors, anchors used in tunnel, bridge and street construction or in general in above and below ground construction, are the means best known to impart the required strength to construction works or to brace them, fasten them or keep them in place. However, similar means are also used in mechanical engineering in order to keep parts together, to assemble them, or to apply forces, to apply them or to deviate them.
As a rule, rod-shaped traction elements are used for such purposes which are anchored, i.e., affixed terminally, whether using screw-tightened laminar elements, wedging elements, screw connections, bolts, bonding, etc. As a rule, tensile or compressive forces will act on the assembled anchor element (s).
These rod-shaped anchor elements or round bars or round steels are metallic and thereby evince substantial weight. Again, anchors are used as rule that are terminally affixed, i.e., "anchored" using screw connections or threads or bolts, and such a feature is undesirable foremost in construction because threads may easily be fouled by dust, sand, gravel etc., and, thus, become rapidly useless.